1. Field of the Invention
The present invention relates to a press button switch and a method of manufacturing the same.
2. Description of the Background Art
In recent years, as for the key top (part exposed from the housing) of press button switches used in cellular phones, or the like, a metallic finish has been used as a design to impart a feeling of high quality. In the following a conventional press button switch comprising the key top with a metallic finish design is described.
FIG. 15 is a cross-sectional view schematically showing the structure of a conventional press button switch. Referring to FIG. 15, the conventional press button switch has a plating layer 101, a molded resin part 103 and a base rubber 104 making up its main parts. The plating layer 101 is formed on the surface of the molded resin part 103 which is a base body of the press button. The molded resin part 103 is bonded to the base rubber 104 by means of the adhesive layer 106. An actuator part 105 is formed to be integrated into the base rubber 104. The actuator part 105 is a part which makes the switching possible by pressing a dome-shaped metal plate 108.
Here, such a press button switch is arranged on a substrate 107 and is arranged so that the key top is exposed from the housing 110.
The plating layer 101 comprises, for example, a chemical nickel plating layer, an electrolysis copper plating layer, an electrolysis nickel plating layer or an electrolysis chromium plating layer.
Conventionally, as described above, a plating is applied onto the surface of the molded resin part 103 so that the key top has the metallic finish design. However, in such a method by means of plating only the color of the metal itself can be selected for the key top design and, therefore, the problem arises that designs cannot be freely created.
As for a method of achieving colors which cannot be created by using only the metal itself, there is a method for carrying out a color coating on the top surface of the plating layer 101. However, color coating is inferior in wear resistant properties and easily comes off. Therefore, when the switching operation is repeated, the color coating comes off and the plating layer 101 is exposed so that the problem arises that unevenness of color occurs.
The present invention provides a press button switch and a method of manufacturing the same which can impart a feeling of high quality through a metallic finish design, of which the design degree freedom is high and of which color unevenness of the key top can be prevented from occurring.
A press button switch according to the present invention is a press button switch for a switching operation through the pressing of a button which comprises a base body of the button, an undercoat layer which is formed on the surface of the base body and of which the surface, at least, exhibits a metallic color and a film which is formed over the surface of the undercoat layer so as to cover the undercoat layer and which allows the transmission of the metallic color of the undercoat layer.
According to a press button switch of the present invention, a formed film is used of which the material quality is superior in wear resistance properties to a coating film. Therefore, the peeling off of the film during usage can be prevented so that unevenness of color due to exposure of the undercoat layer can be prevented from occurring.
In addition, since the film is made of a material which allows the metallic color of the undercoat layer to be transmitted and, therefore, a metallic finish design can be achieved so as to impart a feeling of high quality.
It is preferable for the film to be a color film in the above described press button switch.
Thereby, the film can be colored while reflecting the metallic color of the undercoat layer so that the degree of design freedom can be enhanced.
It is preferable for the film to be a colorless film in the above described press button switch.
Thereby, the metallic color of the undercoat layer can be clearly transmitted.
It is preferable for the above described press button switch to further comprise a layer with transmittance which has a designed pattern between the undercoat layer and the film.
Thereby, the degree of design freedom can be enhanced.
It is preferable for the undercoat layer to be a metal layer in the above described press button switch.
Thereby, an undercoat layer which exhibits a metallic color can be formed by means of plating or vapor deposition.
It is preferable for the undercoat layer to be a printed layer where a plate-type finish is applied to the surface in the above described press button switch.
Thereby, a desired plate-type finish design can be gained by means of printing process so that the degree of design freedom can be enhanced.
It is preferable for the above described press button switch to further comprise a protective film for preventing heat from being conveyed from the base body to the undercoat layer and the protective film is formed between the base body and the undercoat layer.
Thereby, heat can be prevented from being conveyed from the base body side to the undercoat layer so that color change, or the like, of the undercoat layer can be prevented.
It is preferable for the base body to contain an actuator formed for a switching operation in the above described press button switch.
Thereby, it becomes unnecessary to separately provide an actuator from the base body in order to simplify the design of the parts.
It is preferable for the base body to have a hollow area in the above described press button switch.
Thereby, it can be designed to be made lighter.
The method of manufacturing a press button switch according to the present invention is a method of manufacturing a press button switch for a switching operation through the pressing of a button which comprises the step of formation of a film with transmittance in a button shape and, through contact with the button shape of a layered film wherein an undercoat layer, of which the surface exhibits a metallic color, and said film are layered, a base body fixed to said layered film is formed.
In a method of manufacturing a press button switch according to the present invention, a press button switch which can impart a feeling of high quality through a metallic finish design with a high degree of design freedom and which can prevent the unevenness of color through frictional wear from occurring can be manufactured by a simple method.
Here, the step of a formation of the film in a button shape may either be the step of formation of, solely, the film into a button shape or the step of a formation of a film and an undercoat layer in the layered condition in a button shape. When the film is formed, solely, into a button shape an undercoat layer is formed following the shape of the film after the formation.
It is preferable for the base body to be formed after the formation of the film into a button shape in the above described method of manufacturing a press button switch.
Thereby, a precise button shape can be gained.
It is preferable for the base body to be formed simultaneously at the formation of the film in a button shape in the above described method of manufacturing a press button switch.
Thereby, the formation of the base body and the formation into a button shape can be carried out simultaneously and the step thereof can be designed to be simplified.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.